Method and apparatus for encoding/decoding metadata

ABSTRACT

Provided are a meta data encoding/decoding method and apparatus. The meta data decoding method includes decoding a media signal containing a media object, and decoding meta data corresponding to the media object. During the decoding of the meta data signal, decoding of the meta data is skipped when the meta data that is to be decoded is identical to already decoded meta data.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2007-0081440, filed on Aug. 13, 2007, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Methods and apparatuses consistent with the present invention relate todata encoding and decoding, and more particularly, to a method andapparatus for efficiently encoding/decoding metadata and a recordingmedium thereof.

2. Description of the Related Art

Advances in multimedia technologies has triggered development of methodsof satisfying users' various demands for multimedia contents. Meta datais used to quickly and precisely search for desired data out of a largeamount of multimedia data. The meta data is allocated to contentaccording to predetermined rules, and contains various information, suchas the location and the details of the content, the details of a contentproducer, right conditions, usage conditions, and usage history. Themeta data is used in order to represent data and fast search for data.

SUMMARY OF THE INVENTION

The present invention provides an encoding/decoding method and apparatuscapable of determining whether meta data has been updated or whethermeta data is not changed without decoding the meta data.

The present invention also provides an encoding method and apparatus fordetermining whether meta data has been updated or whether meta data isnot changed by using either a cycle of inserting a meta data packet intoa transmission stream or unique location information of the meta data.

The present invention also provides a decoding method and apparatus fordetermining whether meta data has been updated or whether meta data isnot changed by using either a cycle of inserting a meta data packet intoa transmission stream or unique location information of the meta data.

The present invention also provides an encoding/decoding method andapparatus and a data structure for preventing the same meta data frombeing repeatedly decoded by determining whether the meta data has beenupdated or whether the meta data is not changed, and a computer readablemedium having recorded thereon a program for executing the method.

According to an aspect of the present invention, there is provided amethod of decoding meta data, the method including decoding a mediasignal containing a media object; and decoding meta data correspondingto the media object, wherein if the meta data that is to be decoded isidentical to already decoded meta data, the decoding of the meta data isskipped.

The decoding of meta data may include extracting location information ofthe corresponding meta data from the media object; and decoding the metadata having the location information by using the extracted locationinformation. Whether the meta data that is to be decoded is identical tothe already decoded meta data may be determined by comparing theextracted location information with location information of the alreadydecoded meta data, and the location information of the meta data may bea unique identifier of the meta data. If at least one of the mediaobject and the meta data corresponding to the media object is changed,the location information of the meta data may also change. The meta datamay include object description data, wherein the object description datacontains information for decoding the media signal.

According to another aspect of the present invention, there is provideda method of decoding meta data, the method including decoding a mediasignal containing a media object; and decoding meta data correspondingto the media object by using location information of the meta data,which is extracted from the media object, wherein the locationinformation is a unique identifier of the meta data.

According to another aspect of the present invention, there is provideda method of decoding meta data, the method including receiving a streamin which a media signal containing a media object and meta datacorresponding to the media object are mixed together in the form of apacket; parsing the stream into the media signal and the meta datasignal; and decoding the parsed media signal and meta data signal,wherein the meta data packet is inserted into the stream in apredetermined cycle, where the cycle represents whether unique versioninformation of the meta data is updated.

During the parsing of the stream, parsing the meta data packet may beskipped when the cycle of inserting the meta data packet is identical toa previous cycle. The parsing of the stream may include performing themeta data packet when the cycle of inserting the meta data packet is notidentical to a previous cycle.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the attached drawings in which:

FIG. 1A is a diagram illustrating a case where the location informationof meta data contained in a meta data signal is variable;

FIG. 1B is a diagram illustrating a case where the location informationof meta data contained in a meta data signal is invariable, according toan embodiment of the present invention;

FIG. 2 is a diagram illustrating the structure of a meta datatransmission stream according to an embodiment of the present invention;

FIG. 3 illustrates a media meta data framework according to anembodiment of the present invention;

FIG. 4 is a block diagram of a meta data encoding apparatus according toan embodiment of the present invention;

FIG. 5 is a block diagram of a meta data encoding apparatus according toanother embodiment of the present invention;

FIG. 6 is a block diagram of a meta data decoding apparatus according toan embodiment of the present invention;

FIG. 7 is a block diagram of a meta data decoding apparatus according toanother embodiment of the present invention;

FIG. 8 is a flowchart illustrating a meta data encoding method accordingto an embodiment of the present invention;

FIG. 9 is a flowchart illustrating a meta data encoding method accordingto another embodiment of the present invention;

FIG. 10 is a flowchart illustrating a meta data decoding methodaccording to an embodiment of the present invention; and

FIG. 11 is a flowchart illustrating a meta data decoding methodaccording to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention will now be described ingreater detail with reference to the accompanying drawings.

An encoding/decoding apparatus according to the present invention iscapable of determining whether meta data has been updated or whether themeta data is not changed by using location information of meta data or acycle of transmitting the meta data. Meta data contains unique versioninformation, and a change in the version information means that the metadata has been updated. Hereinafter, if meta data has unique locationinformation, a technique of determining whether the meta data has beenupdated by using the location information and a technique of indicatingwhether the meta data has been updated by changing a cycle of insertinga meta data packet into a meta data transmission stream, will bedescribed.

FIGS. 1A and 1B are drawings explaining the present invention using ameta data signal. In detail, FIG. 1A illustrates a case where thelocation information of meta data contained in a meta data signal isvariable, and FIG. 1B illustrates the location information of meta datacontained in a meta data signal is invariable according to an embodimentof the present invention.

Referring to FIGS. 1A and 1B, each of meta data signals 100, 110, and120 contains a plurality of pieces of meta data, and the pieces of themeta data are respectively contained in specific locations of the metadata signals 100, 110, and 120. The meta data signals 100, 110, and 120may include an area for storing undefined meta data, which will now bereferred to as a reserved area or a garbage area for convenience.

In the case of FIG. 1A, the locations of the pieces of the meta datacontained in the meta data signal 100 are variable, i.e., can change.The movement of each piece of the meta data also changes the locationinformation thereof It is assumed that the meta data contained in aleftmost location 00 of the meta data signal 100 has been canceledbecause the meta data has been lost or damaged. In this case, thelocations of the remaining meta data in the meta data signal 100 shiftby one in the left direction since the location 00 is empty. Thus themeta data as originally being contained in a location 01 shifts to thelocation 00, and the location information thereof changes from “01’ to‘00’. Referring to FIG. 1A, the meta data signal 110 is obtained whenthe locations of the pieces of the meta data shift by one in the leftdirection. Since the locations of the meta data are variable, it is notguaranteed that the location of meta data stored at a specific instantof time is maintained at another instant of time and that the samelocation information represents the same meta data.

In the case of FIG. 1B, each of a plurality of pieces of meta datacontained in the meta data signal 100 has unique location information.Thus unless the pieces of the meta data are not changed or deformed,their location information is not changed. As in the above example, itis assumed that the meta data contained in a leftmost location 00 of themeta data signal 100 has been deleted. In this case, the locations ofthe other pieces of the meta data in the meta data signal 100 do notshift even if the location 00 is empty. Thus even if some of the piecesof the meta data in the meta data signal 100 are lost, the uniquelocation information of the remaining pieces of the meta data in a metadata signal 120 is maintained. That is, the location information of themeta data functions as an identifier thereof, and thus the same locationinformation of the meta data represents the same meta data.

A change in a media signal results in a change in meta datacorresponding to the media signal. If meta data is changed due to achange in the media signal or irrespective of the media signal, thechanged meta data is not the same as the original meta data and thus thelocation information of the changed meta data also changes. If it isassumed that meta data in a location 00 is changed as illustrated inFIG. 1B, the location of the changed meta data is also changed. In thiscase, the changed meta data may be contained in a reserved/garbage area.Referring to FIG. 1B, the meta data in the location 00 is changed andthen shifts to a location 20 in a reserved/garbage area.

Hereinafter, various embodiments of the present invention when thelocation information of meta data functions as an identifier thereof asillustrated in FIG. 1B, will now be described in detail.

FIG. 2 illustrates the structure of a meta data transmission stream 200according to an embodiment of the present invention. Referring to FIG.2, in the meta data transmission stream 200, a plurality of mediaobjects contained in a media signal and a plurality of pieces of metadata contained in a meta data signal are mixed together in the form of apacket. Referring to FIG. 2, audio packets, video packet, and meta datapackets contained in the meta data transmission stream 200 arerespectively indicated with “A”, “V”, and “M”. An encoding apparatus(not shown) generates and encodes the media signal and the meta datasignal, and then transforms them in the form of a packet. In this case,the meta data contained in the meta data signal is packed in a sectionstructure and then is divided into units of packets. Version informationis allocated to the section of each piece of the meta data. If a changein version information results in a change in the attributes of the metadata, and thus the version information functions as a unique identifierof the meta data. According to the present invention, a decodingapparatus (not shown) is capable of determining whether the meta datahas been updated, using the version information. To this end, theencoding apparatus can indicate whether the version information of themeta data is not changed, using a cycle of mixing a meta data packet.That is, a multiplexer (not shown) of the encoding apparatus candetermine a ratio at which audio packets, video packets, and meta datapacket are mixed to form a stream. The multiplexer may insert the metadata packets into the stream in a first cycle if the version of the metadata is not changed, and the meta data packets into the stream in asecond cycle if the version of the meta data is changed, that is, if themeta data is updated. Referring to FIG. 2, the encoding apparatussequentially inserts two audio packets, two video packets, and a metadata packet into a stream, and then sequentially inserts an audiopacket, a video packet, and a meta data packet in to the stream in orderto indicate that the meta data is updated. The encoding apparatuschanges a cycle of inserting the meta data according to the versioninformation thereof, inserts the meta data in the changed cycle, andthen transmits the stream containing the meta data to the decodingapparatus.

FIG. 3 illustrates a media meta data framework according to anembodiment of the present invention. Referring to FIG. 3, the media metadata framework includes a media signal 300 and a meta data signal 310.The media meta data framework is obtained by composing meta data basedon media objects. If contents are managed based on a meta data stream,it is difficult to change or capture some media objects from among thecontents since meta data is composed in units of scenes, and damage tothe meta data stream prevents scene composition during contentstreaming. Thus meta data is preferably composed based on media objectscontained in a media signal. If meta data is composed based on mediaobjects, each of the media objects contains information necessary foraccessing the meta data, e.g., the location information of the metadata. The media objects can access meta data corresponding to therespective media objects by using the location information of the metadata.

The media signal 300 may contain an audio signal, a video signal, or animage signal, and a plurality of media objects. Each media objectcontains an audio frame, a video frame or an image frame for each mediasignal. Also, each media object has corresponding meta data, and uniquelocation information of the corresponding meta data.

The meta data signal 310 contains a plurality of pieces of meta data.The meta data contains information regarding the media objects, orsigns, characters or marks, which are defined for object processing andused to perform particular functions. The meta data signal 310 mayfurther include object description data containing various profileinformation, such as information for decoding the media object, andmedia handling data containing information regarding a renderinglocation of the media objects or regarding transforming the mediaobjects.

Each of the media objects may contain location information of the metadata, such as object description data, or media handling data whichcorresponds to each media object, such as location information of themeta data. Referring to FIG. 3, a number is allocated to each of themedia objects in the media signal 300. The allocated number may be usedas version information of the corresponding meta data or in order toindicate the location of the meta data. Each piece of the meta data hasunique version information, and particularly has unique locationinformation according to the present invention. Thus, the versioninformation and the location information have one to one correspondenceto each other, and may be the same according to circumstances.

A decoding apparatus (not shown) can easily access meta datacorresponding to the respective media objects by using the locationinformation of the meta data. The pieces of the meta data contained inthe meta data signal 310 are arranged according to the unique locationinformation thereof.

The decoding apparatus decodes from the leftmost media object in themedia signal 300 to the rightmost media object. In detail, the decodingapparatus first decodes the leftmost media object, and extracts locationinformation 01 of the meta data from the decoded media object. Thedecoding apparatus accesses the meta data at a location corresponding tothe location information 01 by using the extracted location information.As described above, according to the present invention, the locationinformation of the respective pieces of the meta data respectivelyidentify the pieces of the meta data. That is, the location informationcan be used as a unique identifier of the meta data.

The decoding apparatus can reproduce the media signal 300 by using themeta data for the media objects. A user can use the media signal 300from a beginning or middle part thereof. Thus, while reproducing a mediaobject having specific attributes, the decoding apparatus mustrepeatedly decode meta data corresponding to an identical media object.If media objects have the same attributes, meta data corresponding tothe media objects are also the same. That is, the media objects have thesame additional information, such as decoding type, renderinginformation, or title information thereof. Thus once decoding of themeta data for the media object having specific attributes is completed,it is not necessary to repeatedly decode the meta data for an identicalmedia object having the same attributes. According to the presentinvention, the decoding apparatus can determine whether meta data thatis to be decoded is identical to already decoded meta data by usingunique location information for each piece of meta data.

Next the decoding apparatus decodes a second media object contained inthe media signal 300, and extracts location information 01 of the metadata from the second media object. Then the decoding apparatusdetermines whether the extracted location information 01 is identical tothe previously extracted location information 01. The decoding apparatusdoes not access and decode the meta data at a location corresponding tothe location information 01 since the extracted location information 01is identical to the previously extracted location information 01. Thatis, the already decoded meta data never be decoded thus skippingunnecessary decoding. Next the decoding apparatus decodes a third mediaobject in the media signal 300, and extracts location information 03 ofthe meta data from the third media object. The decoding apparatusdetermines whether the extracted location information 03 is identical tothe previously extracted location information 01. The decoding apparatusdetermines that the meta data is updated since the extracted locationinformation 03 is not identical to the previously extracted locationinformation 01. Then the decoding apparatus accesses the meta data at alocation corresponding to the extracted location information 03 based onthe extracted location information 03. Thereafter the decoding apparatusdecodes the accessed meta data, extract attribution information for themedia object from the meta data, and then reproduce the media object byusing the attribution information.

FIG. 4 is a block diagram of an apparatus for encoding meta dataaccording to an embodiment of the present invention. Referring to FIG.4, the encoding apparatus includes a media signal generation unit 410, amedia signal encoding unit 420, a location information generation unit430, a meta data signal generation unit 440, a meta data signal encodingunit 450 and a multiplexer 460. The encoding apparatus allocates uniquelocation information to meta data so that whether the meta data has beenupdated or is not changed can be easily determined.

The media signal generation unit 410 generates a media signal, such asan audio signal or a video signal. The media signal encoding unit 420encodes the media signal and transmits it to the multiplexer 460. Themeta data signal generation unit 440 generates meta data correspondingto each of media objects contained in the media signal. The meta datasignal generation unit 440 generates a meta data signal by arrangingeach of a plurality of pieces of the meta data in a specific location.The meta data contains various profile information, such as theattributes and manufacturing date of the media signal, and informationfor decoding the media signal.

The location information generation unit 430 respectively receives themedia signal and the meta data signal from the media signal generationunit 410 and the meta data signal generation unit 440, determines metadata corresponding to each of media objects contained in the mediasignal, and then generates location information indicating the locationof each pieces of the meta data. As described above, the locationinformation of the meta data enables the meta data to be identified. Thelocation information generation unit 430 transmits the generatedlocation information to the media signal generation unit 410 and themeta data signal generation unit 440. The media signal generation unit410 generates a media signal by inserting the location informationreceived from the location information generation unit 430 into therespective media objects.

The meta data signal encoding unit 450 encodes the meta data signalgenerated by the meta data signal generation unit 440 and transmits theencoded meta data signal to the multiplexer 460. The multiplexer 460transforms the encoded media signal and meta data signal in the form ofa packet, mixes the packets together, and transmits the mixed packets toa decoding apparatus (not shown).

FIG. 5 is a block diagram of an apparatus for encoding meta dataaccording to another embodiment of the present invention. Referring toFIG. 5, the encoding apparatus includes a media signal generation unit510, a media signal encoding unit 520, a meta data signal generationunit 530, a meta data signal encoding unit 540, and a multiplexer 550.The media signal generation unit 510 generates a media signal andtransmits the media signal to the media signal encoding unit 520. Themedia signal encoding unit 520 encodes the media signal and transmitsthe encoded media signal to the multiplexer 550. The meta data signalgeneration unit 530 generates a meta data signal corresponding to themedia signal and transmits the meta data signal to the meta data signalencoding unit 540. The meta data signal encoding unit 540 encodes themeta data signal and transmits the encoded meta data signal to themultiplexer 550. The multiplexer 550 transforms the encoded media signaland meta data signal that are respectively received from the mediasignal encoding unit 520 and the meta data signal encoding unit 540, sothat they can be transmitted. The multiplexer 550 transforms datacontained in the media signal and the meta data signal in the form of apacket, mixes the packets together, and transmits the mixed packets to adecoding apparatus (not shown).

As described above, according to the present invention, versioninformation or location information given to meta data may be used inorder to determine whether the meta data is not changed. The encodingapparatus illustrated in FIG. 5 changes a cycle of insertion of the metadata packet so that the decoding apparatus can determine whether themeta data is not changed or whether the version information of the metadata has been updated by using the version information. To this end, themultiplexer 550 of the encoding apparatus illustrated in FIG. 5 includesa cycle determination unit 551 and a signal mixer 553. The cycledetermination unit 551 determines a cycle of transmitting the meta datapacket by determining a ratio at which the meta data packet, audiopackets and video packets are mixed together in order to indicatewhether the meta data is not changed, that is, whether the meta data hasbeen updated by changing the version thereof. The cycle determinationunit 551 allows the meta data packet to be inserted in a predeterminedcycle if the version of the meta data is not changed, and the meta datapacket to be inserted in a changed cycle if the version of the meta datais changed. The signal mixer 553 performs packet mixing using the cycleof insertion of the meta data packet, which is determined by the cycledetermination unit 551. The signal mixer 553 generates a stream byinserting the meta data packet in the predetermined cycle if the versionof the meta data is not changed, and a stream by inserting the meta datapacket in a different cycle if the version is changed by updating. Thesignal mixer 553 transmits the generated stream to the decodingapparatus.

FIG. 6 is a block diagram of an apparatus for decoding meta dataaccording to an embodiment of the present invention. Referring to FIG.6, the decoding apparatus includes a demultiplexer 610, a media signaldecoding unit 620, a meta data signal processing unit 630 and a mediasignal reproducing unit 640. If unique location information is given tometa data, the decoding apparatus of FIG. 6 determines whether the metadata is not changed, using the unique location information.

The demultiplexer 610 parses an encoded media signal and a meta datasignal received from an encoding apparatus (not shown), and respectivelytransmits the media signal and the meta data signal to the media signaldecoding unit 620 and the meta data signal processing unit 630. Themedia signal decoding unit 620 decodes the media signal and transmitsthe decoded media signal to the media signal reproducing unit 640.

The meta data signal processing unit 630 includes a location informationextraction unit 631, a location information comparison unit 633 and ameta data signal decoding unit 635. The location information extractionunit 631 extracts location information from media objects included inthe media signal. The location information extraction unit 631 transmitsthe extracted location information to the location informationcomparison unit 633.

The location information comparison unit 633 stores the extractedlocation information received from the location information extractionunit 631. If receiving the location information of the new meta datafrom the location information extraction unit 631, the locationinformation comparison unit 633 compares the stored location informationwith location information of the new meta data. The location informationcomparison unit 633 transmits the result of comparison to the meta datasignal decoding unit 635. If the stored location information is notidentical to the location information of the new meta data, the locationinformation comparison unit 633 transmits the location information ofthe new meta data to the meta data signal decoding unit 635. The metadata signal decoding unit 635 determines whether to decode the meta datasignal according to the result of comparison. If the locationinformation of the meta data corresponding to the media object that iscurrently decoded by the media signal decoding unit 620 is not identicalto location information of meta data corresponding to an already decodedmedia object, the meta data signal decoding unit 635 accesses anddecodes the meta data corresponding to the media object that iscurrently decoded. The meta data signal decoding unit 635 transmits thedecoded meta data to the media signal reproducing unit 640. The mediasignal reproducing unit 640 reproduces the media signal by using thedecoded media signal and meta data signal received from the media signaldecoding unit 620 and the meta data signal decoding unit 635.

If the location information of the meta data corresponding to a mediaobject that is currently decoded by the media signal decoding unit 620is identical to the location information of already decoded meta data,the meta data signal decoding unit 635 skips decoding of the meta datahaving the same location information. That a plurality of pieces of metadata having the same location information is understood that the piecesof the meta data are identical to each other, and therefore, it isunnecessary to decode meta data whose version is the same as that of thealready decoded meta data. Accordingly, it is possible to preventunnecessary operation from being performed by skipping redundantdecoding.

FIG. 7 is a block diagram of an apparatus for decoding meta dataaccording to another embodiment of the present invention. Referring toFIG. 7, the decoding apparatus includes a demultiplexer 710, a mediasignal decoding unit 720, a meta data signal decoding unit 730 and amedia signal reproducing unit 740. The decoding apparatus determineswhether the meta data has been updated by using a cycle in which a metadata packet has been inserted into a stream transmitted from an encodingapparatus (not shown). To this end, the demultiplexer 710 includes acycle sensing unit 711 and a parsing unit 713.

The cycle sensing unit 711 senses the cycle of the meta data packetbeing mixed together with the stream. The cycle sensing unit 711 storesthe information regarding the meta data packet cycle, and determineswhether a newly sensed meta data packet cycle is the same as the storedmeta data packet cycle. The parsing unit 713 parses media signalpackets, such as an audio packet and a video packet, transmits theparsed media signal packets to the media signal decoding unit 720,parses a meta data packet, and then transmits the parsed media datapackets to the meta data signal decoding unit 730. The media signaldecoding unit 720 decodes the media signal received from the parsingunit 713 and transmits the decoded media signal to the media signalreproducing unit 740. The parsing unit 713 determines whether the metadata packet must be parsed or not using the meta data packet cyclesensed by the cycle sensing unit 711. If the meta data packet cycle ischanged, it means that the version information of the meta data isupdated and thus the parsing unit 713 parses the meta data packet andtransmits the parsed meta data packet to the meta data signal decodingunit 730. The meta data signal decoding unit 730 receives the meta datasignal from the parsing unit 713 and transmits it to the media signalreproducing unit 740. If the meta data packet cycle is the same as aprevious cycle, it means that the meta data is not changed and thus theparsing unit 713 does not parse the meta data packet. The meta datasignal decoding unit 730 need not repeatedly decode meta data having thesame version information since the parsing unit 713 does not parse metadata having the same meta data packet cycle. The media signalreproducing unit 740 reproduces the media signal by using the decodedmedia signal and the decoded meta data signal received from the mediasignal decoding unit 720 and the meta data signal decoding unit 730.

FIG. 8 is a flowchart illustrating a method of encoding meta dataaccording to an embodiment of the present invention. Referring to FIG.8, a meta data encoding apparatus according to an embodiment of thepresent invention generates a media signal containing media objects(operation 810). Next, the meta data encoding apparatus generates metadata corresponding to the respective media objects, and a meta datasignal containing a plurality of meta data signals (operation 820). Themeta data encoding apparatus generates location information of the metadata corresponding to the respective media objects by using the mediasignal and the meta data signals (operation 830). Then the meta dataencoding apparatus respectively inserts a plurality of pieces of thelocation information into the media objects (operation 840). Thereafterthe meta data encoding apparatus encodes the media signal and the metadata signals and mixes them together.

FIG. 9 is a flowchart illustrating a method of encoding meta dataaccording to another embodiment of the present invention. Referring toFIG. 9, a meta data encoding apparatus according to an embodiment of thepresent invention generates and encodes a media signal containing amedia object (operation 910). The meta data encoding apparatus generatesa meta data signal corresponding to the media object and encodes themeta data signal (operation 920). The meta data encoding apparatustransforms the media signal and the meta data signals in the form of apacket (operation 930). The meta data encoding apparatus generates apacket stream using the packets, and determines a cycle of inserting themeta data packet into the packet stream (operation 940). Next the metadata encoding apparatus generates a stream by inserting a meta datapacket into the packet stream in the determined cycle (operation 950),and then transmits the stream to a decoding apparatus (not shown)(operation 960).

FIG. 10 is a flowchart illustrating a method of decoding meta dataaccording to an embodiment of the present invention. Referring to FIG.10, a meta data decoding apparatus according to an embodiment of thepresent invention decodes a media signal containing a media object(operation 1010). The meta data decoding apparatus extracts locationinformation of meta data corresponding to the media object from themedia object (operation 1020). The meta data decoding apparatusdetermines whether the extracted location information is identical tolocation information of already decoded meta data (operation 1030). Ifthe extracted location information is not identical to the locationinformation of the already decoded meta data, the meta data decodingapparatus decodes the meta data of the extracted location information(operation 1040). If the extracted location information is identical tothe location information of the already decoded meta data, the meta datadecoding apparatus skips decoding of the meta data of the extractedlocation information. Thus it is possible to prevent an unnecessaryoperation from being performed by skipping redundant decoding of thesame meta data, thereby reducing the complexity of the decodingapparatus.

FIG. 11 is a flowchart illustrating a method of decoding meta dataaccording to another embodiment of the present invention. Referring toFIG. 11, a meta data decoding apparatus according to an embodiment ofthe present invention receives a packet stream (operation 1110). Themeta data decoding apparatus senses a cycle in which a meta data packethas been inserted into the packet stream (operation 1120). The meta datadecoding apparatus determines whether the sensed cycle is identical to aprevious cycle (operation 1130). If the sensed cycle is not identical tothe previous cycle, the meta data decoding apparatus parses the metadata packet and transmits the parsed meta data packet to the meta datasignal decoding unit (operation 1140). In this case, the meta datadecoding apparatus decodes the meta data signal packet. If the sensedcycle is identical to the previous cycle, the meta data decodingapparatus does not parse the meta data packet. Also, in this case, themeta data decoding apparatus also does not decode the meta data signal.Accordingly, if a packet cycle is identical to a previous cycle, thesame meta data is not repeatedly decoded thus reducing the complexity ofa decoding operation.

The present invention provides an encoding/decoding method and apparatuscapable of determining whether meta data has been updated or whethermeta data is not changed without decoding the meta data.

The present invention also provides an encoding method and apparatus fordetermining whether meta data has been updated or whether meta data isnot changed by using either a cycle of inserting a meta data packet intoa transmission stream or unique location information of the meta data.

The present invention also provides a decoding method and apparatus fordetermining whether meta data has been updated or whether meta data isnot changed by using either a cycle of inserting a meta data packet intoa transmission stream or unique location information of the meta data.

The present invention also provides an encoding/decoding method andapparatus and a data structure for preventing the same meta data frombeing redundantly decoded by determining whether the meta data has beenupdated or whether the meta data is not changed, and a computer readablemedium having recorded thereon a program for executing the method.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1. A method of decoding meta data, comprising: decoding a media signalcontaining a media object; and performing one of not decoding a secondmeta data and decoding the second meta data corresponding to the mediaobject, wherein if the second meta data is identical to a previouslydecoded first meta data, the second meta data is not decoded in theperforming.
 2. The method of claim 1, wherein the performing thedecoding of the second meta data comprises: extracting locationinformation of the second meta data from the media object; and decodingthe second meta data at the location information by using the extractedlocation information.
 3. The method of claim 2, wherein whether thesecond meta data is identical to the previously decoded first meta datais determined by comparing the extracted location information withlocation information of the previously decoded first meta data, and theextracted location information of the second meta data is a uniqueidentifier of the second meta data.
 4. The method of claim 3, wherein ifat least one of the media object and the second meta data correspondingto the media object is changed, the extracted location information ofthe second meta data also changes.
 5. The method of claim 1, wherein thesecond meta data comprises object description data, wherein the objectdescription data contains information for decoding the media signal. 6.A method of decoding meta data, comprising: decoding a media signalcontaining a media object; and decoding meta data corresponding to themedia object by using location information of the meta data, which isextracted from the media object, wherein the location information is aunique identifier of the meta data.
 7. A method of decoding meta data,comprising: receiving a stream in which a media signal packet containinga media object and meta data packet corresponding to the media objectare mixed together; parsing from the stream, the media signal packet;and decoding the media signal packet, wherein if the parsing from thestream further parses the meta data packet, the meta data packet isinserted into the stream in a predetermined cycle, and the predeterminedcycle represents whether unique version information of the meta data isupdated.
 8. The method of claim 7, wherein during the parsing from thestream, parsing the meta data packet is not performed if thepredetermined cycle is identical to a previous cycle.
 9. The method ofclaim 7, wherein the parsing from the stream comprises parsing the metadata packet if the predetermined cycle is not identical to a previouscycle.
 10. A method of encoding meta data, comprising: encoding a mediasignal containing a plurality of media objects; and encoding meta datacorresponding to the respective plurality of media objects, wherein theplurality of media objects comprise location information of thecorresponding meta data, and the location information are a uniqueidentifiers of the meta data.
 11. The method of claim 10, wherein themeta data comprise object description data for the correspondingplurality of media objects, where the object description data compriseinformation for encoding the media signal.
 12. The method of claim 10,wherein if the plurality of media objects have the same attributes, themeta data corresponding to the respective plurality of media objects areidentical to each other.
 13. A method of encoding meta data, comprising:generating a stream by mixing a media signal containing a media objectpacket and meta data packet for the media object together; andindicating whether unique version information of the meta data packet isupdated, using a cycle of inserting the meta data packet into thestream.
 14. An apparatus for decoding meta data, comprising: a mediasignal decoding unit which decodes a media signal containing a mediaobject; and a meta data signal processing unit which performs one ofdecoding a meta data signal containing second meta data corresponding tothe meta object, and not decoding the meta data signal, wherein if thesecond meta data is identical to a previously decoded first meta data,the meta data signal processing unit does not decode the meta datasignal.
 15. The apparatus of 14, wherein the meta data signal processingunit comprises a location information extraction unit which extractslocation information of the second meta data corresponding to the mediaobject from the media object; a location information comparison unitwhich determines whether the extracted location information is identicalto location information of the previously decoded first meta data; and ameta data decoding unit which decodes the second meta data having theextracted location information if the extracted location information isnot identical to the location information of the previously decodedfirst meta data.
 16. An apparatus for decoding meta data, comprising: ademultiplexer which receives a stream in which a media signal packet anda meta data packet corresponding to the media signal packet are mixedtogether, and parses from the stream, the media signal packet; a mediasignal decoding unit which decodes the parsed media signal packet; and ameta data signal decoding unit which decodes the parsed meta datapacket, if the demultiplexer parses meta data packet, wherein, if themeta data packet is parsed, the meta data packet is inserted into thestream in a predetermined cycle, wherein the predetermined cycleindicates whether unique version information of a meta data of the metadata packet is updated.
 17. The apparatus of claim 16, wherein thedemultiplexer comprises: a cycle sensing unit which senses thepredetermined cycle of inserting the meta data packet and determineswhether the predetermined cycle is identical to a previous cycle ofinserting the meta data packet into the stream; and a parsing unit whichparses from the stream the media signal, and the parsing unit parses themeta data packet if the predetermined cycle is not identical to theprevious cycle.
 18. The apparatus of claim 16, wherein the parsing unitdoes not parse the meta data packet if the predetermined cycle isidentical to the previous cycle.
 19. An apparatus for encoding metadata, comprising: a media signal generation unit which generates a mediasignal containing a media object; and a meta data signal generation unitwhich generates a meta data signal containing meta data corresponding tothe media object, wherein the media object comprises locationinformation of the corresponding meta data, where the locationinformation is a unique identifier of the meta data.
 20. The apparatusof claim 19, wherein the meta data comprises object description data forthe media object, wherein the object description data comprisesinformation for encoding the media signal.
 21. The apparatus of claim19, further comprising a location information generation unit generatingthe location information of the meta data corresponding to the mediaobject by using the media signal and the meta data signal.
 22. Anapparatus for encoding meta data, comprising: a media signal encodingunit which encodes a media signal containing a media object; a meta datasignal encoding unit which encodes a meta data signal containing metadata corresponding to the media object; and a multiplexer whichgenerates a stream by mixing the encoded media signal and the encodedmeta data signal together as a media signal packet and a meta datapacket, wherein the multiplexer changes a cycle of inserting the metadata into the stream to indicate whether unique version information ofthe meta data is updated.
 23. The apparatus of claim 22, wherein themultiplexer comprises: a cycle determination unit which determines thecycle of inserting the meta data into the stream to indicate whether theunique version information of the meta data is updated; and a signalmixing unit which generates the stream by inserting the meta data packetinto the stream in the determined cycle.
 24. A computer readable mediumhaving recorded thereon a method of decoding meta data, the methodcomprising: decoding a media signal containing a media object; anddecoding meta data corresponding to the media object by using locationinformation of the meta data, which is extracted from the media object,wherein the location information is a unique identifier of the metadata.
 25. A computer readable medium having recorded thereon a method ofencoding meta data, the method comprising: encoding a media signalcontaining a plurality of media objects; and encoding meta datacorresponding to the respective plurality of media objects, wherein theplurality of media objects comprise location information of thecorresponding meta data, where the location information are uniqueidentifiers of the meta data.
 26. A computer readable medium havingrecorded thereon a method of decoding meta data, comprising: receiving astream in which a media signal packet containing a media object and ameta data packet corresponding to the media object are mixed together;parsing from the stream, the media signal packet and the meta datapacket; and decoding the parsed media signal packet and meta datapacket, wherein the stream indicates unique version information of themeta data contained in the meta data packet by using a cycle ofinserting the meta data packet into the stream.
 27. A computer readablemedium having recorded thereon a method of encoding meta data, themethod comprising: generating a stream by mixing a media signal packetcontaining a media object and meta data packet for the media objecttogether; and indicating whether unique version information of the metadata packet is updated, using a cycle of inserting the meta data packetinto the stream.